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PubMedDate not supplied

Experiences with the new Audiant XA-II implant and the behind-the-ear (BTE) device.

Patients with large conductive hearing loss do not always tolerate conventional air conduction or bone conduction hearing aids. They can be helped sometimes with an implantable bone conductor device. The so-called bone-anchored hearing aid consists of an implantable titanium skull screw and an external sound processor unit. In this study, we report our experiences with 10 subjects who have been implanted with the recently improved Audiant screw-type XA-II and their experience with the newly developed behind-the-ear (BTE) external processor, the at-the-ear processor and the body-level device with a new transducer with variable magnetic strength. Evaluation shows that the Audiant XA-II system is well accepted and does not show any tissue reaction. The BTE processor is an important new complement to the Audiant system. Furthermore, the system is effective in compensating the air-bone gap almost completely at the higher frequencies but only partially at the lower ones. The maximum output appears to limit its feasibility for perceptive losses beyond 20 dB (PTA). When this system is utilized for proper hearing loss, however, the system usually improves speech intelligibility both in quiet and in background noise. When the system is prescribed for hearing losses with a moderate or large perceptive component, the system is ineffective and leads to negative evaluations.

Adult↗
PubMed1997

From posterior crus stapedectomy to 0.6 mm stapedotomy--towards reliability in otosclerosis surgery.

In the 1980s, in Oulu, clinical otosclerosis was primarily managed with posterior crus stapedectomy and in the 1990s, the method was changed to stapedotomy. This retrospective study was carried out to assess the results of different methods of stapes surgery in the hands of one surgeon. Subsequent primary stapes operations in 1989-1990 (91 operations including 74 posterior crus stapedectomies and 1 Causse stapedotomy) and in 1993-1994 (117 operations including 1 posterior crus stapedectomy, 95 Causse pistons) were analysed. Changes in air and bone conduction thresholds were compared 5 weeks, 7 months and 19 or more months postoperatively. There was a significant difference in hearing (air-conduction-AC and bone-conduction-BC) in favor of Causse 0.6 mm teflon piston prostheses as compared to posterior crus stapedotomies at 7 months and 19 or more months. Likewise, the 4 kHz gain at the same time was also significantly better with Causse 0.6 mm all teflon piston. At 5 weeks, 81% of posterior crus stapedectomies and 78% of Causse stapedotomies had air conduction thresholds within 10 dB of preoperative bone conduction. However, at 7 months, the corresponding figures were 68% and 89%. Re-operations were performed in 26.7% posterior crus stapedectomies but only in 1% Causse 0.6 mm teflon piston stapedotomies. In the hands of the senior author (KL), the change from posterior crus stapedectomy technique to stapedotomy with 0.6 mm Causse teflon piston in primary stapes surgery proved to be successful. Surprisingly, the AC and BC hearing in the Causse stapedotomy group kept on improving during the follow-up.

Follow-Up Studies↗
PubMed1995

Quantifying the Carhart effect in otosclerosis.

The Carhart effect consists of a depression in bone conduction thresholds in the presence of a conductive hearing loss. However, the mathematical relationship between the degree of conductive hearing loss and the degree of depression of bone conduction has not before been described. We have reviewed pre- and post-operative pure-tone audiograms performed on 102 consecutive patients having stapedectomy in an attempt to identify relationships between changes in bone conduction and air conduction and air-bone gap closure. Significant linear relationships were found between bone conduction and air conduction at 0.5. 1, 2 & kHz. Bone conduction was linearly related to air bone gap closure at 2 kHz.

Adolescent↗
PubMed2004

Paediatric small cavity mastoid surgery: second look tympanotomy.

OBJECTIVE: Following surgery for retraction pocket/cholesteatoma there is risk of residual disease, after canal wall up surgery a second look tympanotomy is routinely recommended. After canal wall down (CWDM) surgery this is not routine. In certain situations the senior author recommends second look tympanotomy. This report examines the outcome of this management paradigm applied to small cavity mastoid surgery for children. METHOD: A retrospective review of small cavity mastoid surgery for children with cholesteatoma or discharging retraction pocket disease. The primary procedure and surgical findings at second look tympanotomy are reported as well as the pre- and 1 year post-operative air and bone conduction thresholds and air-bone gap averaged across frequencies 0.5, 1, 2 and 4kHz and the mean pre- and post-operative bone conduction threshold at 4kHz. A Student t-test was used to compare hearing results. RESULTS: Forty five were children reviewed at 1 year. Twelve (27%) were recommended second look tympanotomy, of which 10 had surgery; all were free of residual disease. At second look two children had ossiculoplasty performed, four had adhesions divided. Six children had formed a myringostapediopexy after their first surgery. The mean pre-op bone conduction threshold was 6.3dB for those having single stage surgery and 5.6dB for those having a second look and the post-operative thresholds were 7.8 and 10.2dB, respectively. The mean preoperative air conduction threshold was 32.6dB for single stage surgery and 31.1dB for staged surgery and at 1 year 29.2 and 40.8dB. This was a significant difference. After second look, the air conduction threshold was 34.5dB, and not significantly different from those who had single stage surgery. The mean pre-treatment 4kHz bone conduction threshold was 6.3 and 5.6dB for single stage surgery and second look tympanotomy and after surgery, respectively, 9.8 and 14.5dB. These changes are not statistically significant. CONCLUSION: The small cavity mastoidectomy approach allows meticulous removal of disease from the middle ear and for certain indications second look tympanotomy is recommended. Planned second look tympanotomy has demonstrated excellent early disease control as well as allowing timely management of any pathology affecting the middle ear sound transformation mechanism.

Adolescent↗
PubMed2004

Clinical, experimental, and theoretical investigations of the effect of superior semicircular canal dehiscence on hearing mechanisms.

HYPOTHESIS: A superior semicircular canal dehiscence affects hearing by introducing a third window into the inner ear that 1) lowers cochlear input impedance, 2) shunts air-conducted sound away from the cochlea resulting in conductive hearing loss, and 3) improves bone-conduction thresholds by increasing the difference in impedance between the vestibule and the round window. BACKGROUND: Superior semicircular canal dehiscence has been linked to a "conductive" hearing loss characterized by a decrease in the sensitivity to air-conducted sound and hypersensitivity to bone-conducted sound. METHODS: Four investigations were performed: 1) laser-Doppler vibrometer measurements of sound-induced umbo velocity in patients with computed tomographic scan-confirmed superior semicircular canal dehiscence; 2) laser-Doppler vibrometry of sound-induced motions of the vestibular lymph (either perilymph or endolymph) exposed in a chinchilla model of superior semicircular canal dehiscence; 3) studies in chinchillas of the effect of superior semicircular canal dehiscence on the cochlea's sensitivity to bone-conducted sounds; and 4) anatomically based theoretical analyses of sound flow through the human cochlea and semicircular canals. RESULTS: The low-frequency umbo velocity in superior semicircular canal dehiscence patients without previous middle ear surgery ranged from normal through high normal. This tendency toward hypermobility suggests a decrease in cochlear impedance. Measurements of sound-induced velocity of the lymph within a superior semicircular canal dehiscence in chinchillas demonstrated sound flow through the dehiscence. Measurements of the cochlear potential demonstrated a superior semicircular canal dehiscence-induced increase in response to bone-conducted sound in eight of nine chinchillas. An anatomically based model of the human ear predicts changes in auditory sensitivity similar to audiometric changes in superior semicircular canal dehiscence. CONCLUSION: The results suggest that superior semicircular canal dehiscence can affect hearing function by introducing a third window into the inner ear.

Animals↗
PubMed1985

Afferent influences on brain stem auditory nuclei of the chicken: effects of conductive and sensorineural hearing loss on n. magnocellularis.

Nucleus magnocellularis is the avian homologue of the spherical cell region of the mammalian anteroventral cochlear nucleus. Its primary excitatory synaptic input is from large end bulbs of Held from the eighth nerve ganglion cells. We have examined the effects of three peripheral manipulations--middle ear ossicle (columella) removal (monaural and binaural), columella removal and oval window puncture (monaural), and monaural earplug--on cross-sectional cell area ("cell size") of second-order auditory neurons in n. magnocellularis of the chicken. Manipulations were performed between embryonic day 19 and posthatch day 4. Survival time was varied from 2 to 60 days. Air conduction and bone conduction thresholds were determined to assess for conductive and sensorineural hearing loss associated with each of these manipulations. Hair cell counts were made from basilar papillae of each experimental group. We found that a columella removal alone, which produced a 50-55-dB purely conductive hearing loss, was not associated with changes in cell size of n. magnocellularis neurons. Similarly, chronic monaural earplugging did not affect the cross-sectional area of these second-order auditory neurons. Conversely, a combined columella removal and oval window puncture, which produced a mixed hearing loss with a 15-40-dB sensorineural component was associated with an 18-20% reduction in n. magnocellularis cell area. Hair cell counts for experimental ears were not significantly different from control ears. These results, in conjunction with measurements of multiunit activity recorded in n. magnocellularis, suggest that manipulations which markedly attenuate extrinsic auditory stimulation, but do not result in chronic change in the average activity levels, also do not influence the size of n. magnocellularis cell bodies. On the other hand, a manipulation which influences overall activity levels, but does not result in degeneration of receptor cells, resulted in marked changes in n. magnocellularis cell size.

Afferent Pathways↗
PubMed1977

Deafness after bacterial meningitis.

Seventeen children with previous bacterial meningitis and 17 sib controls were examined clinically and otoscopically. They were also tested with air-conduction and bone-conduction audiometry and evaluated by tympanometry. There were no major neurological abnormalities and few otoscopical signs of ear disease. 21% of the ears showed abnormalities on air-conduction audiometry but all were normal on bone-conduction audiometry. 30% had abnormal middle-ear pressures (more negative than 100 mm water) on tympanometry and 7% had abnormal compliance of the drum. There were no significant differences on any test between the postmeningitis children and the sib controls. Population studies have confirmed that minor hearing loss due to middle-ear dysfunction is common in children, but is probably temporary in most of them. We have found no excess of middle-ear dysfunction and no sensorineural deafness in these postmeningitis children, but other workers have shown that nerve deafness may occur in association with clinical neurological damage. However, much of the deafness attributed to bacterial meningitis in other studies may well reflect population variability.

Child↗
PubMed1989

[The effect of occlusion. Part I. The mechanism].

To clarify the mechanism of the occlusion effect the following experiments were performed on 18 healthy and 4 patients with conductive impairment: 1) measurement of the improvement in bone conduction threshold after the ears were covered with occluding devices of different volumes (earphones and calibrated spherical glass enclosures), 2) measurements of sound pressure level (SPL) changes in the meatus under the same conditions. The increase of SPL under covers was found, which was parallel to the improvement of bone conduction threshold in covered ears. Both phenomena were closely related to the volume of the enclosures: the larger the volume the smaller the change in SPL and in the threshold shift was found. In ears with a conductive loss--only the SPL was increased without any change in the bone conduction threshold. It was concluded that the occlusion effect is caused by the resonance phenomena in close meatus: the increased SPL induces the bone conducted threshold shift via the normal conductive apparatus (bone-air conduction). That explains the lack of threshold changes in conductive lesions. In the open meatus acoustic energy radiated by the bony walls becomes dissipated.

Auditory Threshold↗
PubMed1991

The induction of bone by an osteogenic protein and the conduction of bone by porous hydroxyapatite: a laboratory study in the rabbit.

The influence of the addition of an osteoinductive protein, capable of inducing extraskeletal ossification, on bone ingrowth into coralline porous hydroxyapatite was evaluated in the rabbit using a calvarium onlay model. Twenty-three rabbits received hydroxyapatite implants (10 x 10 x 2 mm) prepared with and without osteoinductive protein. These were implanted on the frontal bone and secured by wire fixation after 0.25 mm of the cortical surface was abraded. The implants were harvested at 3 and 4 months and analyzed for percentage of bone ingrowth by histologic examination of decalcified H&E sections and by scanning electron microscope backscatter image analysis. The osteoinductive protein-treated implants demonstrated significantly greater amounts of bone ingrowth at both 3 (52.0 versus 10.3 percent; p less than 0.001) and 4 months (66.1 versus 39.2 percent; p less than 0.005) than the untreated implants. The type of bone found in all osteoinductive protein-treated implants was predominantly lamellar. Untreated implants contained mostly woven bone at 3 months, with increasing amounts of lamellar bone appearing at 4 months. These results suggest that the combination of a bone-inducing protein and a suitable osteoconductive matrix may provide an alternative to bone grafting.

Animals↗
PubMed1993

Effect of total ablation of the external acoustic meatus and bulla osteotomy on auditory function in dogs.

Seven dogs with end-stage bilateral otitis externa were evaluated for auditory function before and after bilateral total ear canal ablation and lateral bulla osteotomy. Evaluations were performed by owner questionnaire and by recording brainstem auditory-evoked responses. Prior to surgery, all dogs could hear a loud voice or noise, however, only 3 dogs responded to a voice spoken at a normal level. Of the 14 ears tested electrodiagnostically, only 1 did not have a response, using air-conducted or bone-conducted stimuli. After surgery, 2 dogs responded to a normal voice, but all 7 responded to loud voices or noise. Three ears that had recordable brainstem auditory-evoked responses to air-conducted stimulation prior to surgery, failed to respond after surgery. Ears that responded to bone-conducted stimulation prior to surgery also responded after surgery.

Animals↗
PubMed1991

[Implantable hearing aids].

The purpose of these hearing aids is to improve the quantity and quality of amplification of the sound wave. Their operating principle is based on the existence of a transducer which transforms the electric signal captured by the microphone into a mechanical, vibrating wave. This transducer can act either directly on the temporal bone by short-circuiting the middle ear (and is then called a bone conduction implant) or directly on the ossicular chain (in which case it is called an ossicular transduction implant). A) There are 2 types of bone conduction implant: the "Audiant Bone Conduction" system of Hough-Vernon (Xomed), where an outside electromagnetic coil sends signals transcutaneously to a magnetic screw embedded on the temporal bone. Bone conduction must be normal. The "Bone Anchored Hearing Aid" (Nobelpharma) where the outside electromagnetic coil sends signals directly to the magnetic screw that is percutaneous. The mean thresholds in bone conduction can reach up to 45 dB. The drawbacks of this system lie in its inaesthetic appearance and the risk of infection. B) With ossicular transduction implants, the transducer may be: either an electromagnetic coil influencing a magnet fixed to the tympanum, on the ossicular chain, or replacing an element of the ossicular chain (these hearing aids are marketed by Richards); or a piezo-electric crystal which produces vibrations when it is subjected to an AC current, and which can be positioned on the stapes (Yanagihara). This system consumes less energy, gives excellent results for the high frequencies, but is more cumbersome.

Bone Conduction↗
PubMed2006

Auditory function in patients with surgically treated superior semicircular canal dehiscence.

OBJECTIVE: To characterize preoperative and postoperative audiologic findings in patients with superior semicircular canal dehiscence syndrome. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Patients with documented superior semicircular canal dehiscence syndrome (according to history, vestibular testing, and high-resolution computed tomography imaging) who underwent surgical repair of their dehiscence. INTERVENTION: Middle fossa craniotomy for superior semicircular canal plugging and/or resurfacing. MAIN OUTCOME MEASURES: Audiologic testing both before and after surgery with pure-tone threshold measurements of air and bone conduction. RESULTS: Twenty-nine subjects underwent surgical repair of superior semicircular canal dehiscence. Overall, there were no statistically significant differences by paired t test in hearing before or after surgery, in either air-conduction or bone-conduction thresholds, for 19 patients that had no previous surgical history. At least partial closure of air-bone gap was achieved in five patients. One patient with previous stapes surgery had significantly worse hearing both before and after canal repair compared with those without previous surgery. Two patients who had undergone previous middle fossa surgery with incomplete resolution of symptoms developed sensorineural hearing loss after revision surgery. Previous middle-ear exploration and tympanostomy tube placement did not seem to affect audiologic outcomes. Surgical hearing results did not differ according to method of canal repair (plugging versus resurfacing). CONCLUSION: Primary middle fossa repair of superior semicircular canal dehiscence is not associated with sensorineural hearing loss and, in some cases, can lead to normalization of conductive hearing loss. Revision middle fossa repair or previous stapes surgery may be associated with postoperative sensorineural hearing loss.

Adult↗
PubMed2006

Audiometric analyses confirm a cochlear component, disproportional to age, in stapedial otosclerosis.

OBJECTIVE: To report the preoperative audiometric profile of surgically confirmed otosclerosis. STUDY DESIGN: Retrospective, multicenter study. SETTING: Four tertiary referral centers. PATIENTS: One thousand sixty-four surgically confirmed patients with otosclerosis. INTERVENTIONS: Therapeutic ear surgery for hearing improvement. MAIN OUTCOME MEASURES: Preoperative audiometric air conduction (AC) and bone conduction (BC) hearing thresholds were obtained retrospectively for 1064 patients with otosclerosis. A cross-sectional multiple linear regression analysis was performed on audiometric data of affected ears. Influences of age and sex were analyzed and age-related typical audiograms were created. Bone conduction thresholds were corrected for Carhart effect and presbyacusis; in addition, we tested to see if separate cochlear otosclerosis component existed. Corrected thresholds were than analyzed separately for progression of cochlear otosclerosis. RESULTS: The study population consisted of 35% men and 65% women (mean age, 44 yr). The mean pure-tone average at 0.5, 1, and 2 kHz was 57 dB hearing level. Multiple linear regression analysis showed significant progression for all measured AC and BC thresholds. The average annual threshold deterioration for AC was 0.45 dB/yr and the annual threshold deterioration for BC was 0.37 dB/yr. The average annual gap expansion was 0.08 dB/year. The corrected BC thresholds for Carhart effect and presbyacusis remained significantly different from zero, but only showed progression at 2 kHz. CONCLUSION: The preoperative audiological profile of otosclerosis is described. There is a significant sensorineural component in patients with otosclerosis planned for stapedotomy, which is worse than age-related hearing loss by itself. Deterioration rates of AC and BC thresholds have been reported, which can be helpful in clinical practice and might also guide the characterization of allegedly different phenotypes for familial and sporadic otosclerosis.

Adult↗
PubMed1996

[The influence of age and previous thresholds on stapedectomy results].

This is a retrospective study dealing with 719 primary stapedectomies and 48 reoperations done between 1975 and 1993 by the AA. of the paper. They consider the audiometric tracings before and after surgery (6 and 12 months). Frequencies analyzed were 250 Hz, 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz; the air-bone gap; and modifications of bone thresholds. The patients were ranged in groups according the ages and previous bone thresholds. Thereafter an analysis aiming to a comparison of surgery results en each group was contemplated. The age resulted without influence on the postoperative gap neither in modifications of bone conduction. The previous bone thresholds nor influencing the final gap. Conversely there are significative differences (P > 0.01) regarding the modifications of bone conduction.

Adult↗
PubMed2001

Hearing rehabilitation using the BAHA bone-anchored hearing aid: results in 40 patients.

OBJECTIVE: This study evaluates the U.S. experience with the first 40 patients who have undergone audiologic rehabilitation using the BAHA bone-anchored hearing aid. STUDY DESIGN: This study is a multicenter, nonblinded, retrospective case series. SETTING: Twelve tertiary referral medical centers in the United States. PATIENTS: Eligibility for BAHA implantation included patients with a hearing loss and an inability to tolerate a conventional hearing aid, with bone-conduction pure tone average levels at 60 dB or less at 0.5, 1, 2, and 4 kHz. INTERVENTION: Patients who met audiologic and clinical criteria were implanted with the Bone-Anchored Hearing Aid (BAHA, Entific Corp., Gothenburg, Sweden). MAIN OUTCOME MEASURES: Preoperative air- and bone-conduction thresholds and air-bone gap; postoperative BAHA-aided thresholds; hearing improvement as a result of implantation; implantation complications; and patient satisfaction. RESULTS: The most common indications for implantation included chronic otitis media or draining ears (18 patients) and external auditory canal stenosis or aural atresia (7 patients). Overall, each patient had an average improvement of 32+/-19 dB with the use of the BAHA. Closure of the air-bone gap to within 10 dB of the preoperative bone-conduction thresholds (postoperative BAHA-aided threshold vs. preoperative bone-conduction threshold) occurred in 32 patients (80%), whereas closure to within 5 dB occurred in 24 patients (60%). Twelve patients (30%) demonstrated 'overclosure' of the preoperative bone-conduction threshold of the better hearing ear. Complications were limited to local infection and inflammation at the implant site in three patients, and failure to osseointegrate in one patient. Patient response to the implant was uniformly satisfactory. Only one patient reported dissatisfaction with the device. CONCLUSIONS: The BAHA bone-anchored hearing aid provides a reliable and predictable adjunct for auditory rehabilitation in appropriately selected patients, offering a means of dramatically improving hearing thresholds in patients with conductive or mixed hearing loss who are otherwise unable to benefit from traditional hearing aids.

Acoustic Stimulation↗
PubMedDate not supplied

High frequency audiometry.

After a brief discussion of the past use of and clinical need for high frequency hearing tests, a new technique is described that uses a special electric transduction mode: a 60-kHz carrier frequency is modulated by the desired audiofrequency. The combined signal is applied to the skin over the mastoids by Mylar-covered electrodes. On perception, the audiofrequency part of the input shows all the properties of a bone-conduction signal. The carrier frequency is dispersed in the tissues. Production and calibration of electrical high frequency signals, up to 20 kHz, is straightforward and easier than that of conventional air-conduction and (vibromechanical) bone-conduction signals. The efficacy of the method is illustrated by means of preliminary hearing tests conducted on several subjects.

Animals↗
PubMed2006

[Study on the correlation between sensorineural hearing loss and secretory otitis media].

OBJECTIVE: To explore the correlation between sensorineural hearing loss (SHL) and otitis media with effusion (OME). METHOD: The data of 38 cases with OME who had no recovery of bone conduction hearing threshold were reviewed. The bone conduction hearing thresholds at different frequencies in both healthy and suffering ears were measured and their relationship with age, duration, character and amount of effusion were also discussed. RESULT: At different frequencies, the bone conduction hearing thresholds of the suffering ear were higher than those of the healthy ear (P < 0.05). The older of the age and the longer of the duration, the more possibility of SHL occurrence. Its occurrence was more likely to appear in patients with mucous effusion than in patients with serous effusion, however, it had no relationship with the amount of the effusion. CONCLUSION: OME may lead to SHL, and the etiology and mechanism is complicated and unclear. The patients with older age, longer duration and mucous effusion are more susceptible to SHL, and should be early diagnosed and managed.

Adolescent↗
PubMed2005

Does pregnancy affect otosclerosis?

OBJECTIVE: To evaluate the effect of pregnancy on the hearing of women with otosclerosis. STUDY DESIGN: A retrospective study of women who had undergone stapedectomy. The women were equally divided into two groups: one group with children and a control group without children. Air and bone conduction, as well as discrimination, were measured before and after stapedectomy in both groups. PATIENTS: Ninety-four women (47 with children and 47 without) were evaluated. Because many of the women had bilateral otosclerosis, the total number of ears studied was 128. RESULTS: Mean pure tone air and bone conduction thresholds were not worse in women with children versus those women without children. In fact, mean pre- and postoperative pure tone air and bone conduction thresholds from 500 Hz through 4,000 Hz in women with children were slightly but significantly better than women without children. There was no difference in discrimination scores between groups. Within the group with children, no significant correlation was found between number of children and hearing loss. Also, no correlation was found between breastfeeding and the amount of hearing loss. CONCLUSION: We found no adverse effect on hearing in otosclerotic women who had children compared with women without children. Even with increasing numbers of pregnancies, no deleterious impact was noted. Air conduction, bone conduction, and discrimination were not worse in women with children versus childless women. No significant correlation was found between the number of children and hearing loss, and neither did breastfeeding affect the amount of hearing loss.

Adult↗